Prokaryotic cells. pro = before karyon = nucleus

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2 Prokaryotic cells A prokaryotic cell is a cell which has no nucleus or other organelles with a membrane around them. An example of a prokaryotic cell is a bacteria. pro = before karyon = nucleus

3 Prokaryotic cells DO NOT HAVE Nuclei Mitochondria Endoplasmic reticulum Prokaryotic cells DO HAVE Naked, circular DNA, loose in cell Small ribosomes Possibly plasmids Cell wall (murein) CCEA SPEC

4 Structure of Prokaryotic cells BACTERIUM

5 Electron micrograph of a E. coli bacterium

6 Structure of Prokaryotic cells

7 Eukaryotic cells Animal and plant cells have a nucleus and are termed eukaryotic cells. eu = true karyon = nucleus

8 Eukaryotic cells have Membrane bound nucleus Chromosomes (helical DNA with histone protein coat) Can develop a mitotic spindle Microtubules Large Ribosomes Membrane bound organelles: Mitochondria Endoplasmic reticulum Golgi apparatus Vesicles Lysosomes CCEA SPEC

9 Structure Capsule Cell wall Plasma membrane Ribosomes Mesosomes Mitochondria Chloroplasts Golgi apparatus RER and SER Nucleus DNA prokaryotic cell made of murein small DNA loose in cell coil, no histones eukaryotic cell made of cellulose large chromosomes, histones

10 Structure of animal cells ANIMAL CELL

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13 A Plant Eukaryotic cell PLANT CELL

14 Nuclear pore

15 Chloroplast nucleus nucleolus Cell wall vacuole mitochondrion Starch grain

16 Tim & Moby

17 Mitochondrion Chloroplast Rough endoplasmic reticulum Ribosomes Golgi apparatus Lysosomes Microtubules Plasmodesmata Nucleus Use following websites to prepare a power point. You must include a diagram on one slide and the function on the next.

18 Outer membrane separated from a folded inner membrane by an inter-membrane space A fluid matrix is found in the inner cavity.. Folds of the inner membrane, called cristae, are covered in stalked particles. These enzyme complexes release energy during aerobic respiration to form energy rich ATP (adenosine triphosphate). Cells that are metabolically active contain many mitochondria e.g. cells involved in active transport.

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21 Inside an outer membrane is a network of flattened sacs called thylakoids. Thylakoids are stacked to form grana that have a large surface area for the space they take up. Photosynthetic pigments and enzymes are found on and in the thylakoid membranes. Between the outer membrane and the thylakoids is the stroma. Large starch grains and small lipid droplets are found in the stroma; products of photosynthesis. Most abundant in palisade mesophyll cells of leaves

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25 System of membranous tubes, studded with ribosomes, running through the cytoplasm Distributes/transports substances (especially proteins) throughout the cell. Found in cells that manufacture lots of protein e.g. pancreatic cells that make digestive enzymes

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29 Non-membrane bound organelles Composed of 2 sections that are made in the nucleolus of the nucleus. Found attached to RER or free in the cytoplasm. Site of protein synthesis. Found in huge numbers in all cells.

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31 smooth Endoplasmic Reticulum (ser) System of membranous tubes running through the cytoplasm. Site of lipid and steroid synthesis.

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35 Curved stack of flattened membrane bound sacs. Small vesicles join the cis surface from the RER and others bud off the trans surface. Stores and chemically modifies substances produced in the cell, ready for secretion e.g. carbohydrates are added to proteins here to form glycoproteins such as mucin.

36 Nucleus side

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40 vesicles containing modified protein bud off trans face Exocytosis through plasma membrane vesicles join cis face of golgi body Vesicle containing protein buds off RER rough ER nucleus

41 Small vacuoles pinched off the golgi apparatus that contain hydrolytic enzymes (lysozymes). These enzymes are used to digest protein in old organelles, substances taken up by the cell and even complete cells. Draw diagram page 35 Froggy

42 Digestive enzymes membrane

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45 Rigid hollow rods found in the cytoplasm. The centriole is a pair of short microtubules positioned at right angles to each other. Found in a clear area called the centrosome just outside the nucleus. Each centriole is composed of 9 triplets of microtubules arranged at an angle. At cell division the centrioles move to opposite poles of the cell and produce the spindle that organises and separates the chromosomes. NOT FOUND IN PLANT CELLS

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47 Spindle fibres

48 Strands of cytoplasm that connect plant cells through the cell wall. The plasma membrane of one plant cell is continuous with the next. Allows substances to pass easily between cells.

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51 Electron micrograph of a liver (eukaryotic cell) nucleus

52 Surrounded by the nuclear envelope, a double membrane containing nuclear pores. The outer membrane is covered with ribosomes; this is where RER originates. Inside the nucleus is a large dense area called the nucleolus. This is where ribosomes are made. They are made in 2 parts, leaving the nucleus through the nuclear pores and assembling in the cytoplasm.

53 Nuclear envelope Nuclear pore Nucleolus Nucleoplasm Euchromatin Heterochromatin

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55 Inside the nuclear membrane the nucleoplasm contains chromatin, made up of DNA attached to proteins called histones. At cell division chromatin condenses, wrapping into tight structures called chromosomes. The chromatin of non-dividing cells is spread out throughout the nucleus. Areas of chromatin that are actively being transcribed (copied) appear light under the microscope and are called euchromatin. Areas that are not being expressed are more tightly wrapped, appear dark and are called heterochromatin.

56 DNA HISTONE BEADS

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58 Plant cell walls are composed of cellulose. The cell wall is freely permeable to water and dissolved substances. Cell walls of adjacent cells are glued together by a sticky substance composed of calcium pectate called the middle lamella. As a cell matures it adds layers of cellulose and lignin below the cell wall. This adds strength to the cell and is called the secondary cell wall. The original cell wall is then called the primary cell wall.

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61 Middle lamella

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63 Animal Plant Fungus Lacks chloroplasts Has no cell wall Has centrioles May have glycogen granules (carbohydrate storage) Possesses chloroplasts Has a cell wall composed of cellulose Has vacuole Have starch grains (carbohydrate storage) Have plasmodesmata Often have many nuclei Has a cell wall composed of chitin Have glycogen granules (carbohydrate storage)

64 Identifying tem photographs

65 Levels of organisation Page 40 Froggy Take notes worksheet